The present invention relates generally to fluid lubricant dispensing equipment, and more particularly to a pistol-grip grease gun that can be operated in either pressure mode or volume mode.
A pistol-grip grease gun has a rigid handle and a pivoting lever that are sized and positioned so the gun can be operated with only one hand. A dual-mode grease gun has an adjustment to select between a volume mode and a pressure mode. The volume mode of operation allows a user to apply as much lubricant per stroke into a grease-fitting as possible. The pressure mode of operation allows lubricant to be provided at a greater pressure, such as when a grease-fitting is frozen, impeding the flow of lubricant, or when a bearing being lubricated has a close tolerance such that getting lubricant into it requires more pressure. It is desirable to have a pistol-grip grease gun that can operate in both the volume mode and the pressure mode.
One such dual-mode pistol-grip grease gun is disclosed in U.S. Pat. No. 5,277,339 (“the '339 patent”) assigned to Alemite LLC. The grease gun disclosed in that patent includes a shiftable link which allows a user to switch between operation in volume and pressure modes. However, the link in the '339 patent may be difficult to shift between the two modes of operation because the lever must be pressed down (in a direction axial to the piston) in order to release the link from the end portion of the U-shaped slot, before it may be shifted from volume mode to pressure mode.
Accordingly, a dual-mode pistol-grip grease gun which is able to be easily shifted between volume and pressure modes is desired.